Polymer Li-Ion Single Cell Battery 3.7V 3000mAh 90*70mm 357090

From the shop's description

These are very slim, extremely light weight batteries based on the new Polymer Lithium Ion chemistry. This is the highest energy density currently in production. Each cells outputs a nominal 3.7V at 3000mAh & Dimentions 90*70 mm These batteries require special charging. Do not attempt to charge these with anything but a specialized LiPo charger. Battery includes built-in protection against over voltage, over current, and minimum voltage